Oral surgery final year prep

Frenectomy

A frenum is a fold of tissue or muscle connecting the lips, cheek or tongue to the jawbone. A frenectomy is removal of one of these folds of tissues. Patients receiving dentures may need a frenectomy if the position of a frenum interferes with the proper fit of the denture thereby frequently ulcerating and reducing the stability of the denture. Procedures performed on the labial frenum and lingual frenum are termed as labial frenectomy and lingual frenectomy. Technique- 1. Simple excision 2. Z-Plasty 3. Localised vestibuloplasty with secondary epithelialisation 4. Laser assisted frenectomy Labial frenectomy • Local infiltration anaesthesia is used to anaesthetise the labial frenum at its origin and insertion. • Once anaesthetised, upperlip is everted so that the frenum is kept taut. • Using two haemostats, the fibres of the frenum are locked (the first haemostat is placed parallel to the labial surface of the alveolar ridge and in contact with the mucosa covering the labial surface of the mucobuccal fold and the second haemostat is placed parallel to the lip and perpendicular to the first haemostat). • The haemostats are kept in such a way that their tips touch each other so that the entire fibrous tissue of the frenum which has to be removed lies within the haemostat. • Using a No. 11 BP blade the frenum is excised by cutting the outer surface of both the haemostats so that the excised tissue comes out separately along with the haemostats. • Now the lateral margins of the wound are undermined and the wound is sutured without tension. Lingual frenectomy This procedure is performed when there is ankyloglossia (tongue-tie) or when there is high lingual frenal attachment. This attachment binds the tongue to the lingual surface of the alveolar ridge. Lingual frenectomy is performed in these patients even when prosthesis is not required as it interferes with the normal speech. Once the teeth are lost, it disturbs the stability of the denture each and every time when the tongue is moved. Technique • A 3-0 silk suture is passed through the midline of the tongue around 2 cm from the tip (traction suture). • This is done to hold the tongue up so that the frenum becomes taut. • Using a sharp scissors, a cut is made 1-2 cm midway between the tip of the tongue and the lingual surface of the mandible. • The cut is made in such a way that the blades of the scissors are parallel to the floor of the mouth. • Care should be taken not to injure the submandibular duct, papilla and the blood vessels in the floor of the mouth. • In certain cases genioglossus muscle should also be dissected in addition to the lingual frenum. • The wound margins are undermined, approximated and closed without tension.

Alveoloplasty

A well-contoured smooth ridge is essential for proper construction of denture. While contouring the ridge, it is highly essential to remember that greater the excision of bone, greater will be the resultant resorption. Therefore, the procedure of contouring should be limited to the excision of irregular sharp ridges and unfavourable undercuts which are unsuitable for the denture construction. Goals of alveoloplasty: • To provide optimal ridge contour quickly. • The alveolar ridges should be left as broad as possible for maximum distribution of the masticatory load. • The ridge need not be perfectly smooth but sharp irregularities should be removed and the edges should be rounded. • The mucosa covering the ridge should have uniform thickness, density and compressibility for even transmission of the masticatory forces to the underlying bone. • In younger patients, less amount of bone should be removed as the process of resorption extends for longer number of years than the older patients. a. Primary alveoloplasty- the trimming and removal of the labiobuccal alveolar bone along with some interdental and interradicular bone and is carried out at the time of extraction of teeth. Indications: • Patients with prominent and dense alveolar bone undergoing extraction. • Done as a procedure prior to the construction of an immediate denture. Technique: When alveolar bone remodelling surgery is done at the time of extraction of teeth, the technique is named primary alveoloplasty. • The crevicular incision is placed along free gingival margin and a full thickness mucoperiosteal envelope flap or a triangular flap is elevated which extends up to one tooth distance on either side of the sockets. • A sharp cutting rongeurs forceps is held with one beak beneath the bony rim of the socket and the other on the crest of the ridge. • Small pieces of required amount of bone are removed and bone file is used to smoothen the bone. • The mucous membrane is then held with sutures over the interradicular bony septa. • If any excess flap is present, it is trimmed away and the edges are approximated. • In case of immediate denture, the previously prepared template is fitted on and noted for the presence of any pressure points indicated by the blanching of the mucosa under the transparent acrylic template. If such pressure points are present, they should be trimmed again. Dean's intraseptal primary alveoloplasty: This procedure helps in eliminating anterior maxillary undercuts and reducing the large anterior maxilla by removing the interseptal bone between the teeth. -involves preparation of six anterior teeth and sometimes the premolars are included. The advantage of this technique is that since it retains much of the compact labial cortical bone, it reduces resorption of the bone postoperatively. According to Dean, the most posterior teeth should be removed first to preserve the integrity of labial cortical plate and avoid any disturbance to its blood supply. Dean's intraseptal alveoloplasty is based on the following biological principles: • The prominence of the labial and buccal alveolar margin is reduced to facilitate the reception of dentures • The muscle attachments are undisturbed • The periosteum remains intact • The cortical plate is preserved as a viable onlay bone graft with an intact blood supply • Because the cortical bone is spared, postoperative resorption is minimised. Indications: • To decrease gross maxillary overjet • Adequate bone height • Multiple extractions Technique: • Incision is made along the gingival margin with epithelial attachment (crevicular incision) and interdental papilla attached to the respective teeth. • An envelope flap is raised as conservatively as possible. • Now the teeth are extracted starting from the canine to the incisors. • After extraction of the teeth, the interradicular bony septa should be removed with a rongeur forceps or rotatory drill introduced into the socket to separate the labial and palatal cortical plate. • A V-shaped excision of the bone is done in the labial cortical plate distal and posterior to the canine eminence as close to the alveolus as possible. • Thus three sides of the labial cortex become free and the labial cortex becomes a freely movable osteoperiosteal graft attached to only the mucoperiosteum from which it receives its blood supply. • Now finger pressure is applied to the labial cortical plate which is collapsed towards the socket. Sutures are placed to stabilise the tissues. b. Secondary alveoplasty- • When bone corrective surgery is done on the edentulous ridge for irregularity after the initiation of extraction socket healing, it is termed as secondary alveoplasty. A sharp knife-edge like edentulous ridge causes great denture irritation. They are usually found in the anterior part of the mandible. Localised tenderness over such ridge on palpation or on wearing denture is common. The ridge may also show an irregular pattern known as feather edged ridge. • Incision should be made on the crest of the alveolar ridge. • Usually an envelope flap would suffice, but releasing incision can be made on the labial or buccal side to provide a broad base to the flap. • Bony contouring is accomplished with bone files, rongeurs or burs. • The ridge is made free of sharp irregularities and is not aimed at perfectly smooth ridge requiring excessive bone removal. Digital palpation can be used to determine the uniformity of the ridge. • Once satisfying results are obtained, the region is irrigated copiously with saline to remove debris, small avascular bone pieces at risk of necrosis and the flaps closed.

Clark's vestibuloplasty

Clark's technique is the reverse technique of the Kazanjian's technique. It is based on the following principles: • Raw surface on connective tissue contracts, whereas when covered with epithelium will have minimum contracture. • Raw surface on bone does not undergo contracture. • For repositioning and fixation, epithelial flap must be undermined adequately. • Soft tissues which are repositioned tend to return to their normal position, therefore over correction is necessary. -Flap is pedicled off from the lip, the raw surface on the bone is left exposed. • An incision is made slightly labial to the crest of the alveolar ridge. • The dissection is carried out supraperiosteally till the desired depth of the sulcus. • The lip mucosa is undermined up to the vermilion border so that free edge of the mucosal flap is secured to the periosteum deep in the sulcus. • The raw surface on the bone heals by granulation tissue formation and epithelialisation without contracture. Initially the depth of the sulcus is maintained for a long time. Drawback of the technique is that relapse is common since the attachment of the lip musculature to the alveolar bone shifts towards the alveolar crest, obliterating the sulcus.

Lidocaine- Short note

Classification- Amide Chem formula- 2-Diethylamino 2, 6- acteoxylidide hydrochloride Potency=2 Toxicity=2 Metabolism= liver- microsomal fixed function oxidases, to monoethylglyceine and xylidide Excretion- via kidneys Vasodilating properties- Considerably less than those of procaine pka- 7.9 pH of plain solution- 6.5 pH of vasoconstrictor containing solutions- 5 to 5.5 Onset- Rapid Effective dental conc-2% Anesthetic half life- 1.6 hrs Allergy to amide very rare -Most widely used LA in med & dentistry -3 formulations- 2%without vasoconstrictor(5-10min) -2% with 1:50000(3-5hrs; 60min-pulpal anesthesia) -2% with epinephrine 1:100000(same as above:)) For hemostasis- 2% lidocaine with 1:50000 epinephrine- decreases bleeding by 50%

Obwegeser vestibuloplasty

Combination of buccal and lingual vestibuloplasty- • The lingual sulcus is first deepened as described by Trauner. • Genioglossal fibres are detached leaving the medial and inferior fibres to maintain muscular control of the tongue. • The mylohyoid muscle attachment is detached next. • Now the labiobuccal vestibule is deepened as described by Obwegeser for skin graft vestibuloplasty. • The edges of the buccal and the lingual flaps along with mylohyoid are sutured to each other below the inferior border of the mandible with the help of awl. Entire alveolar ridge is now covered with skin graft. • A previously prepared stent is lined with a split thickness skin graft and is ligated to the mandible with circumferential sutures. The stent is removed after 7-10 days.

Classification of mand fractures

Dingman and Natvig anatomic classification a.Midline:between central incisor b.Symphysis:within the area of midline of the mandible c.Parasymphysis: Bounded by vert lines distal to the canine teeth d.Body: From distal symphysis to line coinc with alv bord of masseter ms(usually including 3rd molar) (between canine region& angle) e.Angle: Triangular reg bounded by ant bord of masseter ms to post-sup att of masseter ms (distal to third molar) f. Ramus: Bounded by superior aspect of the angle to two lines forming apex at sigmoid notch g. Condylar process: Area of condylar process sup to ramus region h. Coronoid process: Includes coronoid process of mandible superior to ramus region i. Dentoalveolar process: region that would normally contain teeth II. Kazanjian and Converse classification: by presence or absence of serviceable teeth in relation to line of fracture. helpful in determining treatment. Class I: Teeth present on both sides of fracture line Class II: Teeth present only on one side of fracture line Class III: Patient is edentulous III. Kruger and Schilli classification 1. Relation to external environment a. Simple or closed b. Compound or open 2. Types of fracture a. Incomplete b. Greenstick c. Complete d. Comminuted 3. Dentition of jaw wrt use of splints a. Sufficiently dentulous jaw b. Edentulous or insufficiently dentulous jaw c. Primary and mixed dentition 4. Localisation a. Fractures of symphysis between canines b. Fractures of canine region c. Fractures of body of mandible between canine and angle of mandible d. Fracture of angle of mandible in third molar region e. Fractures of mandibular ramus between angle of mandible and sigmoid notch f. Fractures of coronoid process g. Fractures of condylar process IV. Spiessel classified mandibular fracture based on 1. Number of fragments (F) 2. Location of fracture (L) 3. Status of the occlusion (O) 4. Soft tissue involvement (S) 5. Associated fracture (parallel fracture of the facial skeleton) (A) Classification of fractures by number of fragments and presence of a bone defect (F0-F4) • F0: Incomplete fracture • F1: Single fracture •F2: Multiple fracture • F3: Comminuted fracture • F4: Fracture with a bone defect (fracture with bone loss) Classification of fractures by site (L1-L8) • L1: Precanine • L2: Canine • L3: Postcanine • L4: Angle • L5: Supra-angle • L6: Condylar process • L7: Coronoid process • L8: Alveolar process Classification of fractures by Occlusal displacement (O0-O2) • O0: No malocclusion • O1: Malocclusion • O2: Nonexistent occlusion (edentulous mandible) Classification of fractures by soft tissue involvement (S0-S4) • S0: Closed • S1: Open intraorally • S2: Open extraorally • S3: Open intra- and extraorally • S4: Soft tissue defect Associated fractures (A0-A6) • A0: None • A1: Fractures or loss of tooth • A2: Nasal bone • A3: Zygoma • A4: Le Fort-I • A5: Le Fort-II • A6: Le Fort-III classification of mand angle and body fractures relates to direction of fracture line & effect of muscle action on frac fragments as: 1. Favourable a. Vertically favourable b. Horizontally favourable 2. Unfavourable fractures a. Vertically unfavourable b. Horizontally unfavourable Vertical fractures have resistance to medial pull ;horizontal fractures have resistance to upward pull. Favourable fractures: muscle pull resists displacement of fractured fragments Unfavourable fractures- muscle pull distracts fractured fragments away from each other, result displacement Horizontally favourable:fracture line passes from alveolar margin, downward and forward, upward displacement of posterior segment is prevented by physical obstruction caused by body of mandible. Horizontally unfavourable: If fracture line passes downward and backward, upward displacement of posterior segment is unopposed. Sometimes upward displacement can be prevented by the presence of a tooth on the posterior segment which comes into contact with maxillary tooth. Masseter, temporalis and medial pterygoid cause upward displacement. Medial pterygoid causes upward and medial displacement of the proximal segment. Horizontal fractures are best seen in lateral oblique and OPG. Vertically favourable-fracture line passes from the outer or buccal plate obliquely backward and lingually- resist muscle pull in medial direction. Vertically unfavourable-fracture line runs from the inner lingual plate obliquely backwards and buccally, result- medial displacement. Vertical fractures are best seen in occlusal radiograph (for viewing buccolingual direction). Muscles responsible—medial pterygoid & lateral pterygoid cause medial displacement of proximal segment.

Classification of local anesthetics

Esters- Of Benzoic acid- 1.Butacaine 2.Cocaine 3.Ethyl aminobenzoate 4.Hexylcaine 5.Piperocaine 6.Tetracaine Para amino benzoic acid 1.Chloroprocaine 2.Procaine 3.Propoxycaine Amides- 1.Articaine 2.Bupivacaine 3.Dibucaine 4.Etidocaine 5.Lidocaine 6.Mepivacaine 7.Prilocaine Quinolones- Centbucridine

Clinical features of mand features

Extraoral examination • Indirect signs: Swelling, ecchymosis, erythaema, abrasion, lacerations Laceration or contusion in chin indicate symphyseal injury-causing symphysis fracture with or without bilateral condyle fracture • Facial deformity: obvious deformity in bony contour of mand, if considerable displacement has occurred, patient unable to approximate the anterior teeth together, mouth remains in open posture (open bite). • Inability to occlude teeth: Exc angle, ramus and condyle, all mand fractures are compound into the mouth and bloodstained saliva is freq dribbling from the corners of mouth. • Palpation- begin bilaterally in condylar region ,continue downwards and along lower border of mandible. Bone tenderness is almost pathognomonic of a fracture, even undisplaced fracture. Displaced fracture present as palpable step deformity in lower border, crepitus from movement of fracture ends. Intraoral examination • Buccal or lingual sulci examined for ecchymosis or clots • On the lingual side, mucosa of the floor of the mouth overlies periosteum of mand, which, if breached foll a fracture, will invariably be cause of any leakage of blood into the lingual submucosa-causing sublingual haematoma (Coleman's sign). Small linear haematomas, (particularly in the third molar region), are reliable indicators of adjacent fracture. • Step defects in occlusion/alveolus along with any obvious lacerations of overlying mucosa and gingival tear • Change of occlusion -one of the significant sign which suggests mandibular fracture. Change of occlusion might be caused due to a fractured tooth, fractured alveolar process, fractured mandible or due to trauma to the TMJ. • Mobility between frac segments-elicited by palpation. • Any pain, tenderness or limitation of movement during full range of mandibular movements is indicative of fracture

Management of mand fractures

Factors of special consideration are as follows: 1. Restoration of mand form & projection. 2. Occlusion-based on the wear facets present the pre-existed occlusion is determined and restored. 3. Stable fixation for early use of jaw to withstand masticatory forces. 4. Restoring the normal TMJ movements and function. 5. In case of displaced fracture compressing inferior alveolar nerve, fracture reduction and fixation should relieve nerve compression. Reduction of fracture: means the restoration of functional alignment of bone fragments. In mand, reduction must be anatomically precise where teeth are present. presence of teeth provides an accurate guide. two types: 1. Closed reduction by manual manipulation of teeth/ gradual reduction by elastic traction done, e.g. simple and undisplaced fractures can be reduced by closed method. 2. Open reduction by direct vision, i.e. by exploration of fracture (e.g. widely displaced, multiple fractures are reduced by open method). Closed reduction Indications -Favourable fractures: Closed reduction reduces the risk of morbidity. Grossly comminuted fractures: Excellent blood supply of the face would facilitate the small fragments of the bones to coalesce and heal, whereas open reduction would jeopardise the vascular supply of the fragments. -Fractures of the severely atrophic edentulous mandible: Open reduction would require the stripping of the periosteum which is the major source of blood supply to the edentulous mandible. Therefore, closed reduction should be the treatment of choice. -Lack of soft tissue overlying the fracture site: Bone plates, screws, wires would interfere with the bone union by further disrupting the soft tissue covering. -Fractures in children involving the developing dentition: Open reduction might pose a risk to the developing tooth bud. -Infected fractures: Infected fracture may create life-threatening surgical risk and delayed healing, hence closed reduction is indicated. -Condylar fractures: Mostly treated by closed reduction when there is minimal disturbance in occlusion and in cases of nondisplaced fracture. -Open reduction Indications • Unfavourable fractures at the symphysis or body or angle of the mandible. • Displaced bilateral condylar fractures. • Delayed treatment of displaced fracture fragments. • Malunited mandibular fractures. • Mandibular fracture opposing an edentulous maxilla. • Edentulous mandibular fracture with severe displacement. • When closed reduction is contraindicated for medically compromised patients (e.g. severe seizure disorders, psychiatric or neurologic problems). • Complex facial fractures: Such fractures can be reconstructed best after open reduction and fixation of the mandibular segments to provide a stable base for restoration. • Other fractures: open reduction with primary bone grafting in fractures of a severely atrophic edentulous mandible with severe displacement of fracture segments or a nonunion after closed reduction of a severely atrophic edentulous mandible fracture. Open reduction and internal fixation with two miniplates along Champy's lines of osteosynthesis for displaced symphysis fracture. Open reduction and internal fixation of parasymphyseal fracture. Open reduction and internal fixation of body fracture According to Champy's lines of osteosynthesis. Surgical approaches for the management of mandibular fractures: dep on various criteria like level of fracture, existing laceration, other associated fractures, surgical exposure, cosmetic concern and type of fixation. Adequate exposure is necessary for proper reduction and fixation of fracture. 1. Preauricular approach. 2. Transparotid approach. 3. Retromandibular approach. 4.Submandibular approach. 5. Postauricular approach. Through existing laceration In some fractures, access to fracture fragment is done through already existing lacerations following Langer's line or relaxed skin tension lines -Mandible approached using existing laceration. Intraoral vestibular approach: simple and commonly used approach for fracture of symphysis, body and parasymphysis. -Incision is made through mucosa in vestibule approx 5 mm away from attached gingiva (in the mucogingival junction). -Care should be taken reg mental nerve, when incision is extended posterior to the canine.Vestibular approach for mandibular body fractures- incision placed sup to mental nerve Intraoral approach to symphysis. Post vestibular approach- preferred for fracture of body, angle, ramus of mandible. -Skeletonisation (freeing of mental nerve) should be done for better retraction of soft tissues. The nerve to be taken care of in posterior vestibular approach is the sensory buccal nerve which crosses the upper anterior rim of the ascending mandibular ramus in the region of the coronoid notch which is at risk of transsection which on injury causes numbness in the buccal mucosal region. Therefore, to protect the nerve, the posterior dissection is to be extended bluntly as soon as the lower coronoid notch is reached Submental approach -used to treat ant mand body and symphysis fractures. These fractures are usually approached and treated by the intraoral approach, but based on the difficulty or severity of the fracture, or the presence of a laceration in that region, can mandate the use of an extraoral approach via the submental route Intraoral approach to the angle. Submental approach. Submandibular approach Submandibular extraoral approach is mainly indicated for fractures which are not suitable by intraoral approach; also it allows satisfactory manipulation of fragments, good control of lingual cortex. mostly used in communited fractures and atrophic mandible. Incision is placed 2-3 cm below the inferior border of the mandible. Care taken for marginal mandibular nerve, facial artery and vein which are encountered during this approach. Length of incision depends on extent of fracture line and type of internal fixation technique. Retromandibular approaches This approach is mainly used for condylar head and neck or ramus as it exposes the entire ramus from behind the posterior border. Main structures in this approach are the retromandibular vein and the facial nerve Preauricular approach Preauricular approach is mainly used for mandibular condylar head and neck fractures Fixation- Rigid/ semirigid fixation achieved by-direct or indirect techniques. Transosseous wiring by Hayton-Williams technique for open reduction and fixation of angle fracture. Open reduction internal fixation (ORIF) of mandible angle fracture. OPG shows two radiolucent lines. Intraoperative observation of a single fracture line indicates its oblique course from buccal to lingual cortex. ORIF of combination fractures (right body and left angle). Immobilisation of fracture- Foll accurate reduction of the fragments,fracture site must be immobilised to allow bone healing to occur. Period of intermaxillary fixation depends upon the type, location, number and severity of mandibular fracture, patient's general health condition, age and method employed for reduction and stabilisation: recommended immobilisation period for mandibular fractures correlates with bony callus stage of secondary bone healing. • Average recommended immobilisation period for mandibular fractures is 6 weeks. • Treatment of edentulous mandibular fractures with closed reduction techniques requires a longer period of IMF when compared with dentate patients. • Age-related bony changes, including thinner mandible and a decreased cancellous volume contribute to the increased immobilisation period required for bony union. Guide to the time of immobilisation of fractures involving tooth-bearing area (Killey and Kay). Young adult with fracture of angle receiving early treatment in which tooth is removed from fracture line—3 weeks. If: a. Tooth retained in fracture line, add 1 week b. Fracture at symphysis, add 1 week c. Age 40 years and above, add 1 week d. Children and adolescents, subtract 1 week Management of teeth in line of fracture Teeth in line of fracture are potential source of infection, interfere with healing of the fracture in the foll manner: • pulp might become necrotic as a result of trauma to the teeth which acts as a source of infection • involvement of teeth makes fracture compound into mouth with exposure of periodontal ligament • The teeth may have some preexisting periapical lesion According to Killey and Kay, indications for removal of a tooth from fracture line are- Teeth which need to be retained in the fracture line. • Tooth which is intact but present in the line of fracture and shows no evidence of mobility or inflammation can be retained with antibiotic coverage. • Second molar in posterior segment of fracture should be retained to prevent superior displacement of posterior fracture segment during intermaxillary fixation. • Attempt to save cuspids, which are the cornerstone of occlusion.

Ideal ridge requirements

Goodsell had recommended the following criteria for a healthy and ideal edentulous ridge for dental rehabilitation: • Adequate bony support for the dentures—the bony ridge should have adequate width and height and U-shape for a denture to be retentive and efficient. • The bone should be covered with adequate soft tissue—the covering oral mucosa should have adequate uniform thickness. • The ridge should not have any undercut or sharp ridges. • No bony or soft tissue protuberances should be present. • It should have adequate buccal and lingual sulci depth. • It should not have any scar bands that prevents normal seating of the denture. • No muscle fibres or frena should dislodge the prosthesis. • Relation of maxillary and mandibular ridge should be satisfactory in all the planes. • No soft tissue hypertrophies or redundancies should be present on the ridge or the sulci.

Classification of preprosthetic procedures

Hard tissue surgeries -Alveolar ridge preservation • Extraction techniques • Preservation of uninfected root stumps -Alveolar ridge augmentation Mandibular augmentation procedures • Superior border augmentation • Inferior border augmentation • Visor osteotomy • Interposition bone grafting (modified visor osteotomy) • Maxillary augmentation procedure • Onlay grafting • Sinus lift • Maxillary and mandibular augmentation • Alveolar ridge distraction • Augmentation in combination with orthognathic surgery Alveolar ridge correction • Alveoloplasty Primary alveoloplasty Secondary alveoplasty • Tori removal Maxillary torus or torus palatinus Mandibular tori or torus mandibularis Mylohyoid ridge reduction Genial tubercles reduction Maxillary tuberosity reduction Tuberoplasty Orthognathic surgery Soft tissue procedures 1)Frenectomy -Labial frenectomy -Lingual frenectomy 2)Vestibuloplasty or ridge extension procedures a)Labiobuccal vestibuloplasty of maxilla • Mucosal advancement vestibuloplasty • Maxillary pocket inlay vestibuloplasty • Grafting vestibuloplasty b)Mandibular vestibuloplasty techniques • Labial approach -Kazanjian's technique -Godwin's technique -Lipswitch vestibuloplasty -Clark's technique c)Lingual vestibuloplasty -Trauner's technique -Caldwell's technique d)Combination of buccal and lingual vestibuloplasty -Obwegeser's technique 3) Redundant tissue excision -Alveolar flabby ridge (hypermobile soft tissues on the alveolar ridge) -Denture granuloma -Epulis fissuratum (inflammatory fibrous hyperplasia, denture fibrosis) -Reactive inflammatory hyperplasia of the palate -Mental nerve transposition 4) Repositioning of inferior alveolar nerve (IAN) -IAN lateralisation (IANL) -IAN transposition (IANT)

Complications of BSSO

Injury to neurovascular bundle- Continuity of bundel should be maintained throughout the process Malpositioning of cond segment- Improper transosseous wiring can push or pull cond segment in untoward position - When maxillomand fixation released, open bite most common presentation req surg recorrection. Bad split, multiple undesirable splits- Wrong splits at ling cortical plate. Poor split- dt removal of last molar at time of surgery- hence advisable to remove 3rd molars 6months before surgery. Excessive bleeding- Occur from inf neurovasc bundle, facial vessels, medullary bed, rarely retromand vein. - Except for facial vessels- bleeding controlled by local measures. - facial vessels- identified, ligated. -Chanelled retractor with cup- hold inf border prev injury to facial vessels.

Lingual split technique is also called

Kelsey Fry technique, based on its inventor Sir William Kelsey Fry

What is preprosthetic surgery?

Preprosthetic surgery is concerned with the surgical modification of the alveolar process and its surrounding structures to enable the fabrication of a well-fitting, comfortable and aesthetic dental prosthesis. When the natural dentition is lost from periodontal disease, trauma, pathologies as cyst, tumour or extraction, the alveolus and the surrounding soft tissue undergoes variable changes. Some of these changes may be unfavourable for the ridge to undergo dental rehabilitation. There may be: • Bone loss with irregularities • Prominences • Undercuts • Superficial location of mental nerve and foramen with associated soft tissue changes • Scarring and changes in insertion of the perioral muscles • Reduced vestibular depth • Flabby hypertrophic ridge

Advantages of lingual split technique

Quick technique Helps in removal of lingually impacted 3rd molars without much buccal bone removal Helps in reduction of size of residual blood clot by saucerization of socket

Complications of lingual split technique

Swelling Trismus Bleeding Neurologic-Lingual nerve damage- Tongue paresthesia -Inf alv nerve damage- Lower lip paresthesia Fractured lingual plate Loss of tooth into submand & subling space Mand fracture Second molar-Hypersensitivity -Distal perio pocket -Ging recession

Describe vestibuloplasty

Vestibuloplasty is a surgical procedure wherein oral vestibule is deepened by changing the soft tissue attachments. Vestibuloplasty can be done either on the labial or the lingual side. Goals of the surgery • To increase the size of denture bearing area • To increase the height of the residual alveolar ridge Labiobuccal vestibuloplasty of maxilla Different techniques for labial vestibuloplasty are: i. Mucosal advancement vestibuloplasty (submucosal vestibuloplasty) ii. Pocket inlay vestibuloplasty iii. Grafting vestibuloplasty Mandibular vestibuloplasty is performed to deepen the labial/buccal or lingual sulcus. It also involves muscle repositioning. Labial approach: An incision is made deep in the sulcus and supraperiosteal dissection is carried out till the predetermined depth. The raw surface heals by secondary epithelialisation. The drawback of this surgery is that in process of healing the sulcus tends to obliterate due to scar contracture. In order to prevent scar contracture, techniques have been designed to reposition or 'switch' mucosa to cover the raw defect of the deepened vestibule. They are: • Kazanjian's technique • Godwin's technique • Lipswitch technique • Clark's technique Lingual vestibuloplasty- used in patients with extensively resorbed mandible. Mylohyoid and genioglossus muscles attached to the lingual aspect of the mandible interfere with the stability of the prosthesis and try to dislodge them. In these patients, extension of the lingual sulcus (or lowering of the floor of the mouth) can help in increasing the denture retention and stability by increasing the surface area. Following methods are adapted for lingual vestibuloplasty: • Trauner's technique • Caldwell's technique Combination of buccal and lingual vestibuloplasty (Fig. 20.43) Obwegeser's technique

Wound closure in BSSO

Wounds well irrigated with saline Hemostasis achieved foll by 3-0 chromic catgut / vicryl

Mandibular tori

an exostoses located on the lingual aspect of the mandible in the region of the premolar above the mylohyoid line. They may be unilateral or bilateral. Indications for removal • It is removed if lower denture is to be constructed. • It should be removed if there is chronic irritation. • Very rarely, it is removed when the patient fears of malignancy. Technique • Inferior alveolar nerve and lingual nerve block are given along with local infiltration anaesthesia on the tori. • Once anaesthetised, an incision is made on the crest of the alveolar ridge for sufficient length to expose the entire tori. • In case of edentulous patients, incision can be placed on the lingual gingival sulcus. • Soft tissues are elevated using a periosteal elevator to expose the tori. • Using a chisel, bur or rongeur, tori is removed and the rough bony surface is smoothened using a bone file. • Excess soft issue is trimmed, wound irrigated and sutured back. Precaution • To prevent formation of sublingual haematoma, while removing bilateral mandibular tori, the flap should be kept intact in the midline. • A piece of gauze is placed below the torus to be removed to prevent the loss of excised bone into the soft tissues since displacement of bone chips may lead to sublingual space infection

Torus Palatinus

torus palatinus is an exostosis found along the suture line of the hard palate. Not all the tori require to be removed as all of them do not cause prosthetic difficulty. Sometimes the bony exostoses may be present on the buccal buttressing bone. Indications for removal for maxillary tori • Smooth maxillary torus can be ignored but when it is extensively irregular, large and extends beyond the junction of the hard and soft palate and interferes with the postdam seal of the denture, it should be removed. • Sometimes the torus may be subjected to constant trauma during mastication. • When it interferes with normal speech. • When the patient fears of malignancy. Technique • Before surgical excision of the tori an impression should be made and the models prepared. • The tori should be removed in this model and an acrylic stent made. • AY-incision for small tori and a double Y-incision for the large tori is made. A full thickness mucoperiosteal flap is elevated carefully to expose the tori entirely. • The tori is divided by transverse and anteroposterior bur cuts to a depth of 1-2 mm above the level of horizontal palatal shelf in order to prevent any fracture of the palate and perforation into the nasal cavity. • These cut sections are removed with the help of a chisel and mallet. • The surface should be finely smoothened using large bone files or vulcanite bur. The torus can also be removed with the help of rotary burs alone without the use of chisels, but this may cause accidental perforation into the nasal cavity or trauma to the soft tissues. • This area should be copiously irrigated and the mucoperiosteal flap is trimmed accordingly and sutured back. • The acrylic stent which was initially constructed must now be inserted. • This stent supports the flap and prevents any haematoma formation and covers the wound. The stent can be used as long as the wound healing is completed. Complications: The risk of creation of oronasal fistula is more owing to the thin palatal shelf.

Radiographs to study mand fracture

• Periapical dental films The most detailed view and can be used for nondisplaced linear fractures of the body as well as alveolar process and dental trauma. Mandibular occlusal view This view demonstrates the discrepancies in the medial and lateral position of body fractures and also shows anteroposterior displacement in the symphysis. Panoramic radiograph The single most informative radiological study used in diagnosing mandibular fractures is the panoramic radiograph, showing the entire mandible, including condyles. Combination of a posteroanterior view and a pantomogram obviates the need for further radiographs and significantly reduces the overall radiation dose to the patient (Fig. 44.18). Advantages • Simplicity of the technique • Ability to visualise the entire mandible in one radiograph • Good detail Disadvantages • The technique requires the patient to be upright, which may make it impractical in the severely traumatised patient. • It is difficult to appreciate buccolingual bone displacement or medial condylar displacement. • Fine detail is lacking in the TMJ area, the symphysis region and the dental and alveolar process region. • Panoramic radiographic equipment is not present in all hospital radiology facilities. • Inpatient with fracture of symphysis, chin-rest position is very difficult which, in turn, results in distorted view (out of focal trough). Lateral oblique view This view helps in the diagnosis of fracture in ramus, angle and posterior body. Double fracture line When the outer and inner compact plates tend to fracture independently, the fracture line from the outer plate after crossing the tooth root and periodontal ligament reaches the lingual plate at the oblique angle in a different level than the buccal plate creating the double fracture line on lateral oblique view. Posteroanterior view This view demonstrates any medial or lateral displacement of fractures of the ramus, angle, condyle, body and symphysis. Midline or symphyseal fractures can be well visualised. CBCT/CT scan CT scan with 3D reconstruction reveals undisplaced as well as degree of displacement, thus helping in treatment planning. Fractures not evident in OPG are also diagnosed through CT scan.

Aims of preprosthetic surgery

• To provide adequate height, length, breadth, width and shape of residual tissue with which the ridge can support and retain the denture and withstand masticatory stress. • To help in proper speech and deglutition. • Satisfy the aesthetic concerns of the patient. • Remove all the hard and soft tissue protuberances and undercuts. • Provide adequate vestibular depth. • Provide appropriate frenal attachment. • Achieve proper jaw relationship in anteroposterior, transverse and vertical dimension. • Relocate the mental nerve and establish correct vestibular depth. • Reduce the pain and discomfort produced by the denture pressure on a narrow alveolar ridge and unsupported (by soft tissue) alveolus due to the presence of superficial mental nerve or an impacted or buried tooth or root which was asymptomatic prior to denture placement. • Insert endosseous implant.

Bilateral sagittal split osteotomy- intro, indic

-introduced by Obwegeser & Trauner-1957 -Used to correct mand progn & retrognathism. -most versatile mand osteotomy

Describe the steps of the Lingual split technique

1. Incision made on 3rd molar region exposing tooth surr bone. Mucoperiosteal flap elevated- buccal side to expose bone enclosing impac tooth. Vertical stop cut- made in ant end of impacted tooth using chisel. 2. Chisel placed horizontally with bevel facing downwards just below vertical stop cut & horizontal cut made extending backwards. 3. Point of application of elevator- made with chisel by excising triangular piece of bone bound ant by lower end of stop cut & above by ant end of hor cut. 4. Distoling bone now fractured inward by using chisel. Chisel held at 45 degree angle to bone surf & point in direction of 2nd premolar on contralateral side. Cutting edge of chisel kept parallel to ext oblique ridge. Care taken not to keep chisel parallel to int oblique ridge as lingual split can extend to coronoid process. -Few light taps with mallet that separates lingual plate from alveolar bone, hinges inward on soft tissue attached to it. 5. Peninsula of bone which remains distal to tooth and between buccal and lingual cuts is excised. 6. Sharp, pointed, fine bladed straight elevator is applied to mesial surface of tooth and minimum of force is used to displace tooth upward and backward out of socket. 7. As tooth moves backward, frac ling plate displaced from path of withdrawal, facilitating delivery of tooth. -After tooth removed from socket, ling plate grasped in fine hemostats & soft tissues freed from it by blunt dissection. 8. Frac ling plate lifted from wound, completing saucerisation of bony cavity. 9. Bone edges smoothened with bone files, wound irrigated with saline, closed with sutures.

Factors affecting local anesthetic action Factors affecting local anesthesia duration

1. Lower pka=(Affects onset) More rapid onset of action, more RN molecules to diffuse through nr sheath; onset time decreased. 2. Lipid solubility(Anesthetic potency)=Increased lipid solubility= increased potency 3. Non nervous tissue diffusibility(affects onset)- increased diffusibility= decreased time of onset 4. Vasodilator onset-(Anesthetic potency & dilation) Greater vasodilation activity= increased blood flow to region= rapid removal of anesthetic molecules from injection site- decreased anesthetic potency and decreased duration. 1.Individual variation in response to drug administered 2.Accuracy in administration of drug 3.Status of tissues at site of drug deposition 4.Anatomical variation 5. Type of injection administered

Postoperative sequelae

1.Edema- resolves within 2 weeks. 2.Diminished sensation of lips- dt inf alveolar nr injury.

Advantages & disadvantages of BSSO

1.Greater flexibility in repositioning distal tooth bearing segment. 2.Better cancellous bone contact - enhance healing 3.No ext scar and injury to the marginal mand nerve 4.Minimum alteration in position of condyles & muscles of mastication.

Bilateral sagittal split osteotomy- Steps

1.Incision on ant aspect of ramus- down mid ramus- over ext oblique ridge- till 1st molar region- curves down to buccal vestibule. 2.Retracting tissues buccally-before placement of incision-prev exposure of buccal pad of fat( unwanted interference.) 3.Mucoperiosteal flap elevation- above lat aspect of mand- at molar region- until inf border. 4.Medial periosteal elevation -Level of lingula, mand foramen ascertained- deepest concavity of ant bord of ramus. -Dissection above mand foramen, using elevator, lingula exposed subperiosteally. 5.Osteotomy- by cutting bone above lingula. Cut- extends post to mand foramen- -Ant to ant bord of ramus- continued along ext oblique ridge- to 2nd molar region- over lat cortical plate. -Vertical cut in this region- depth of cut minimal- enough to reach cancellous bone- Should include inf border to control the splitting. -After cortical cut completed, small spatula osteotome malleted to site from medial cut to vertical cut. -Osteotome directed laterally to prevent injury to neurovascular bundle(Care taken to preserve it till distal fragment.) 6. Proced repeated on opposite side. 7. Used for advancement & backward positioning of mand. 8. Mand advancement- med pterygoid ms separated from inf border of distal segment with periosteal elevator. Mand setback- med pterygoid & masseter- stripped to prevent displacement of condylar segment posteriorly. -When cond segment overlaps medial tooth bearing segment- overlapping part excised & cond segment allowed to be on cancellous part without tension, (care that proximal segment with ant is in its anat position in glenoid fossa.Most imp step during fixation- to prev condylar sag) 9. Rigid int fixation- with plates & screws/ lag screws- best way of fixation. 10. Other methods - Lower body wiring, upper border wiring, circum ramus body wiring.

Factors in selection of local anesthesia

1.Length of time that pain control is required 2.Potential for discomfort in posttreatment period 3.Possibility of self mutilation in postop period 4.Requirement for hemostasis during treatment 5.Medical status of patient

Methods of inducing local anesthesia

1.Mechanical trauma 2.Low temperature 3.Anoxia 4.Chemical irritants 5.Neurolytic irritants-alcohol,phenol 6.Chemical irritants- LA

Desirable properties- local anesthesia

1.Should not be irritating to tissue to which applied. 2.Should not cause any permanent alteration of nerve structure 3.Systemic toxicity should be low 4.Must be effective regardless of whether injected in tissue or applied locally 5.Time of onset as short as possible 6.Duration of action long enough to permit completion of procedure, yet not so long as to req extended recovery (Bennett) 7. Should have potency sufficient to give complete anesthesia without use of harmful concentrated solutions 8. Should be relatively free from producing allergic reactions. 9. Should be stable in solutions and readily undergo biotransformation in body. 10. Should either be sterile or capable of being sterilized by heat without deterioration.

Modifications of BSSO

1.Trauner & Obwegeser-Horizontal cut just above mand foramen- mesial side of ramus - Vertical cut down the ant border of ramus - Oblique cut through lat cortex towards angle of jaw. -Good technique for mand setback, but poor bone contact for mand advancement. -Aseptic necrosis of angle dt extensive stripping of pterygomasseteric sling. 2.Dalpont-Modified by advancing oblique cut to molar region & making vertical cut through lat cortex. - Main prob- interference between retropositioned distal fragment and mastoid process- where occasional process on facial nerve may occur. 3.Hunsuck- shortened cut through medial cortex of ramuss by taking it only as far as mand foramen- prev occasional shattering of ramus in mand setbacks. 4.Bell, Schendel, Epker- made ant vertical cut, through which whole lower border sectioned through & Through with bur. -Split kept more laterally- by directing fine osteotomes down inner surf of lat cortex- to produce easier splitting & greater protection from inf dental nerve. - Blood supply to ramus preserved- as need to strip pterygomasseteric sling is eliminated.